The present invention relates to a heat accumulator, in particular a latent heat accumulator, which has an inner jacket which contains an accumulator core, an outer jacket surrounding the inner jacket at a distance from it to form an insulation chamber, and two conduits extending from the insulation chamber and including a supply conduit and a return conduit for a heat transporting medium, and wherein a device counteracting heat losses is associated with the conduits.
Heat accumulators of this type are known in the art. One of such heat accumulators is disclosed for example in the U.S. Pat. No. 5,090,474. In this heat accumulator the device which counteracts heat losses through the conduits is formed by convection-blocking elements arranged inside the conduits or a thermal insulation by a heat insulating layer, for example of a foam material arranged on the inner wall of the conduit. The convection blocking elements in the interior of the conduit can be formed for example as spiral shaped elements or similar inserts. They are expensive and are contrary to favorable manufacturing principles. An insulating layer which operates as the thermal insulation on the inner side of the conduits reduces the heat losses only insignigficantly. Especially when in order to obtain a thermal siphon action the conduits must extend at least approximately vertically and then open in the inner jacket with a tubular knee, substantial manufacturing difficulties arise for introducing the inner thermal insulation.